Earlier this year, the Royal Horticultural Society and Defra called on holidaymakers to stop bringing plants back from their foreign holidays, warning it could bring pests and diseases to their gardens.Speaking on a topic close to his heart, the Prince has previously appeared on Countryfile and Gardeners’ Question Time, as well as guest editing Country Life magazine.Last year, he wrote of his personal battles to save the trees: “I have always been mortified by the loss of mature elm trees from almost every part of the countryside I knew and loved as a child, so I had high hopes for an American variety that appeared to be resistant to the disease. The Prince Of Wales at Sandringham Flower ShowCredit:Getty The Prince has spent nearly 40 years transforming the gardens at Highgrove from overgrown and neglected land.He will tell Gardeners’ World viewers about the steps he is taking within the Duchy of Cornwall, which covers 53,000 hectares of land across 23 British counties to avoid the spread of plant diseases and pests.He will also talk about his first-hand experience of diseases such as Dutch Elm Disease, Ash Dieback and Phytophthora Ramorum from his management of the estate.The Prince is understood to have been particularly inspired by a visit to the border force at Heathrow earlier this year, where he learned more about how experts are preventing plant-borne diseases being brought into the country. The gardens at HighgroveCredit:Getty Prince Charles shares a love of trees with his mother, the QueenCredit:BBC The programme edit, including the section of the Prince’s discussion to be broadcast, has not yet been finalised.In the show’s introduction, Frost will say: “Back in February I was invited to a meeting at Highgrove with members from across the horticultural industry to discuss the problem of pests and diseases and what could be done about them.”One of the outcomes was Action Oak – a campaign launched at the Chelsea Flower show to help protect our iconic oak.”It is made up of charities, environmental organisations and land owners who are using their combined knowledge to safeguard the beautiful trees.”Today the Prince has invited me back to Highgrove to explain why we as gardeners also need to do our bit.” Gardeners’ World favourite Monty Don “I planted an avenue of them at Highgrove and then watched, miserably, as many of them succumbed just like the native variety.”Lamenting the devastation caused by Dutch Elm Disease, he added: “The wider problem is that a great many more pests and diseases are now seriously threatening the health of all our native trees, yet public awareness of this situation seems to be frighteningly low.”The episode of Gardeners’ World will air on BBC Two at 8pm on July 18. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. The Prince of Wales is to make a star appearance on Gardeners’ World, imploring British garden lovers to “do their bit” to save native trees.The Prince, a long-term advocate of the natural world, will invite viewers into his gardens at Highgrove to investigate the twin blight of pests and diseases on the UK’s landscape.Telling viewers about his own love of gardening, and how he was introduced to his lifelong passion as a boy, he will echo the advice of experts in asking viewers to take measures to protect their own plots.Imploring them to ensure they get their plants from a reputable place, he is expected to ask amateur gardeners not to bring plants back from their own foreign holidays, to prevent introducing new disease.–– ADVERTISEMENT ––The Prince, a keen gardener, will be interviewed at Highgrove by presenter Adam Frost for an special episode focusing on trees.